Hydrocarbon oils of improved water tolerance and anti-rust characteristics



United States Patent 3,346,353 HYDROCARBON OILS 0F IMPROVED WATER TOL- ERANCE AND ANTI-RUST CHARACTERISTICS Barney R. Strickland, Westfield, and Leonard Berkowitz,

Elizabeth, N.J., assignors to Esso Research and Engineering Company, a corporation of Delaware No Drawing. Filed June 20, 1963, Ser. No. 289,426 6 Claims. (Cl. 44-62) The present invention is generally concerned with improving the overall quality of hydrocarbon oils particularly with respect to their water tolerance and anti-rust characteristics. The invention more particularly relates to pctroleum distillate .fuels and similar hydrocarbon oil products having incorporated therein additive agents singularly adapted to prevent the formation of persistent haze and stable emulsions when such products are contacted with water during handling and storage. The additives 0f the present invention for improving water tolerance and anti-rust characteristics comprise dialkyl dimethyl ammonium nitrites.

Ashless oil-soluble polymeric dispersants have largely displaced metal sulfonates, metal naphthen-ates and similar compounds for use as stabilizing additives in petroleum distillate fuels and related hydrocarbon oil products, because of their increased ability to suspend insoluble degradation products formed in such oils. Sludge and sediment which might otherwise tend to clog fuel lines, orifices, screens and filters through which the oils must pass are held in suspension to a much greater extent by the polymeric additives than by the additive materials formerly employed. These increased dispersive properties, although highly desirable from the standpoint of oil stability, have given rise to water tolerance problems much more serious than those heretofore encountered. The polymeric materials employed as oil stabilizing additives exhibit particularly pronounced tendencies to suspend any water with which the oils come into contact and hence extremely persistent haze and stable emulsions are formed upon contact of oils containing the polymeric additives with water. Since an aqueous phase exists in most tanks and other vessels containing such oils, haze formation and emulsification are almost impossible to avoid. As a consequence, the marketability of distillate fuels, lubricating oils, transformer oils, turbine oils and other petroleum distillate products in which polymeric dispersants are used is often seriously aifected.

Thus, the present invention is broadly concerned with a novel class of additives which are surprisingly etfective as a multi-purpose additives in functioning to increase the water tolerance of petroleum distillate fuels and their anti-rust characteristics. The additives of the present invention may be utilized with similar liquid hydrocarbon oils containing polymeric dispersant additives. In accordance with the present invention, it has now been discovered that the addition of minor amounts of dialkyl dimethyl ammonium nitrite to oils, particularly petroleum distillate fuels, greatly reduces the persistence of haze and emulsions when the products are cont-acted with Water and thus permits their transportation and storage in the presence of an aqueous phase without adverse results such as haze formation and rusting of the containers. The di-alkyl dimethyl ammonium nitrites are those having from about C to C alkyl groups as, for example, dimethyl dicoco ammonium nitrite.

The dimethyl dicoco ammonium nitrite is derived from coconut oil and contains about 55 to 70% of C C alkyl groups. One specific example of this dicoco dimethyl ammonium nitrite contains the following mixture of alkyl groups.

Percent v n n 6 C 45 C 20 1e 9 Oleyl 6 Linoleyl 8 Linolenyl 1 The polymeric dispersant additives primarily responsible for the poor water tolerance of distillate fuels and similar products are widely used commercially and are well-known to those skilled in the art. These dispersants in general are polymers and copolymers of unsaturated organic esters, nitriles and similar monomers containing vinyl, vinylene or vinylidene linkages. The dialkyl dimethyl ammonium nitrites employed in accordance with the invention have been found effective when used in oils containing a wide variety of such polymeric dispersants.

A class of polymeric dispersant additives in conjunction with which the dialkyl dimethyl ammonium nitrites have been found to be particularly effective are those which are prepared by the copolymerization of an alkyl chloropropyleneoxy mixed ester of an unsaturated conjugated dibasic acid with a polymerizable organic monomer containing a vinyl linkage. The alkyl chloropropyleneoxy mixed esters used as one of the components of such copolymers are prepared by first reacting a C to C unsaturated conjugated dibasic acid such as maleic acid, fumaric acid, citraconic acid, mesaconic acid or a mixture of such acids or their anhydrides, when they exist, with a long chain saturated aliphatic alcohol to produce a half ester. Suitable alcohols for this purpose are those containing from about 8 to about 24 carbon atoms per molecule, preferably about 8 to 18 carbon atoms per molecule. Straight chain primary alcohols such as dodecyl, cetyl, eicosyl and docosyl alcohols are preferred, but branchedchain alcohols such as 2-ethylhexanol-1 and C oxo-alcohols, secondary alcohols such as 2-octanol and mixtures of straight and branched-chain alcohols may also be used. Commercially marketed mixtures of alcohols of the requisite chain length, such as those obtained by the hydrogenation of coconut oil may also be used.

The half ester produced in the above manner is then reacted with epichlorohydrin in the presence of either an acidic or a basic catalyst, such as boron fluoride or sodium hydroxide, to produce the mixed ester. The ratio of the half ester to epichlorohydrin in the reaction mixture may range from about 1:1 to 1:4. Addition of the epichlorohydrin takes place through the epoxy group and the chlorine atom is unalfected. The mixed ester may thus contain from 1 to about 3 chlorine atoms.

The mixed ester prepared as described above is then copolymerized with from about /2 to about 20 parts of an unsaturated organic monomer containing a vinyl group in the presence of gamma radiation, a peroxide type catalyst such as benzoyl peroxide, or an azo catalyst such as alpha-alpha azo-bis-isobutyronitrile. Suitable monomers containing vinyl groups include hydrocarbons such as styrene, isobutylene and butadiene; esters such as vinyl propionate and methyl methacrylate; ethers such as divinyl ether; and nitriles such as acrylonitrile and vinyl-acetonitrile. Mixtures of such monomers containing vinyl groups with other copolymerizable materials, long chain alcohol esters of unsaturated conjugated dibasic acids such as lauryl maleate and tallow fumarate for example, may also be used. Vinyl esters of short chain fatty acids, particularly vinyl acetate and mixtures of such esters with fumarate or maleate esters of long chain aliphatic alcohols containing from about 8 to about 20 carbon atoms per moleinvention, the dialkyl dimethyl ammonium nitrite is preferably used in conjunction with a polymeric dispersant which comprises a copolymer of an alkyl-chloropropyleneoxy mixed ester of an unsaturated conjugated dibasic acid and polymerizable organic monomers containing a vinylidene group. As pointed out heretofore, these polymeric dispersants are described in copending application, S.N. 126,531, now US. Patent 3,160,484.

The oils in which the additives of the invention may be incorporated are liquid petroleum distillate products boiling in the range between about 75 and about 900 F. Such products include gasoline, aviation turbo-jet fuels, kerosenes, diesel fuels, transformer oils, turbine oils, heating oils, and lubricating oils. The additives are particularly effective in distillate fuels boiling in the range between about 250 F. and about 750 F. Such fuels include turbojet engine fuels, diesel fuels and heating oils which have particularly poor stability properties and require the use of relatively large amounts of the polymeric dispersant additives. Aviation turbo-jet engine fuels are defined by US. military specifications, MIL-F-5624C, MIL-F- 2552A, and MILF2258A and are generally referred to as JP-4, ]P-5, ]P6 and Turbofuel 1A. Diesel fuels in connection with which the additives of the invention are particularly useful are more fully described in ASTM specification D-975-53T and may be used in stationary, marine and automotive type engines. Typical of the heating oils in which the additives may be employed are those described in ASTM Specification D-396-48T, particularly those in grades 1 and 2 thereof.

The polymeric dispersant additives are generally employed in petroleum hydrocarbon products such as those described above in generally preferred concentrations ranging from about 0.0005 to 1% by weight, preferably in a concentration of from 0.001 to 0.05% by weight. The dialkyl dimethyl ammonium nitrite is utilized in a concentration in the range from about 0.0001 to 0.01% by weight preferably in a concentration of 0.0002 to 0.002% by weight.

Other additives used in conjunction with polymeric dispersants to improve the stability of hydrocarbon fuels, particularly distillate fuels, are tertiary alkyl primary amines. Two alkyl groups, one having 1 to 3 carbon atoms and the other having from 5 to 21 carbon atoms, are attached to a tertiary carbon atom. Particularly preferred compounds are C to C tertiary alkyl primary amines. The dialkyl dimethyl ammonium nitrites of the present invention may be used effectively in oils containing both the polymeric dispersant and the tertiary alkyl primary amine. When the amine is utilized, it is employed in a concentration in the range from about 0.0005 to 0.8 wt. percent, preferably in the range from about 0.001 to 0.02 wt. percent.

The composition of the present invention comprising a polymeric dispersant and a dialkyl dimethyl compound such as dicoco dimethyl ammonium nitrite is particularly effective in increasing the water shedding ability of the base fuel. The composition of the present invention comprising a polymeric dispersant such as described in S.N. 126,531 and dicoco dimethyl ammonium nitrite also markedly increases the anti-rusting characteristics of the composition. It is also more effective in preventing haze after the heating oil blend has been subjected to an accelerated stability test.

In order to further illustrate the invention, a number of tests were carried out with a base fuel with various additives. The base fuel was a petroleum distillate heating oil have the following inspections:

Gravity, API 31.7 ASTM distillation:

Initial boiling pt. F. 364

10% point, F 442 50% point, F 501 90% point, F 561 Final boiling point 606 ASTM pour, F 10 The persistence of the haze formed in this oil upon contact with Water was measured in Waring blender haze tests wherein five milliliters of water and 500 milliliters of the oil were mixed in a Waring blender for a period of five minutes, the oil-water mixture was then allowed to stand for 24 hours, and the amount of light which .was

transmitted through the oil under standardized conditions TABLE I 35 p.p.m. Poly- 35 p.p.m. Poly- 35 p.p.m. Polymerie Dispermeric Disper- No merie Dispersant A} 5 p.p.m. sant A} 5 p.p.m. Additive sant A 1 Dicoco Di- Dicoco Dimethyl Ammomethyl Ammonium Chloride nium Nitrite Warning blender Haze Test, Percent Transmission:

0 Hours 15 4 2.5 Hour 3.0 HourS 19 4.0 Hours 65 24 24.0 H 97 Potential Sediment 2 Mg [100 ML.-- 1. 0 0.0 Potential Haze 6 29 41 31 Busting of Additive, Concentrate Carbon Steel:

1 Day None None 30 Days- None None 1 Copolymer of an alkyl-ehloro propyleneoxy mixed ester. 2 Sediment measured after aging oil 16 hours at 212 F. Aged oil mixed with 2 vol. percent oiwater on a standard shaker.

4 Heavy. 5 Very heavy.

TABLE II 75 p.p.m. Addi- 75 p.p.m. Additive A, 12.5 tive A, 12.5 No. p.p.m. Additive p.p.m. Additive Additive B, 7.5 p.p.rn. B, 7.5 p.p.m.

Dicoco Dimethyl Dicoco Dimethyl Ammonium Ammonium Chloride Nitrite Waring blender Haze Test Percent Transmission:

Hours 35 85 2 Hours 1. 73 100 3 Hours 65 24 Hours 97 Potential Haze after Accelerated Aging 6 41 0 Additive AzCnz-u. tertiary 'alkyl primary amine; Additive BzCopolymer parts of beta dimothyl methacrylate ester of mixed coconut oil alcohols, predominating in lauryl alcohol, i.e., the methacrylic ester of technical lauryl alcohol obtained by reduction of the fatty acids of coconut oil. (U.S. Patent 2,560,588, column 3, lines 13 to U.S. Patent 2,721.877, column 3, lines 17 to 31; U.S. Patent 2,737,4o2, column 3,

lines to 42.)

From the above it is apparent that the dialkyl dirnethyl amrnonium nitrites of the present invention are very effective in enhancing the anti-rust and the water resistant properties of the base fuels when other additives such as polymeric dispersants are utilized.

What is claimed is:

1. A liquid petroleum distillate oil boiling in the range between about 75 F. and about 900 F. to which have been added:

from about 00005 to 1 wt. percent of an ashless oilsoluble polymeric dispersant stabilizing additive selected from the group consisting of (a) a copolymer of an alkyl chloropropylene-oxy mixed ester of an unsaturated conjugated dibasic acid and a polymerizable organic monomer containing a vinyl group and (b) a nitrogen-containing addition-type copolymer of an amine-free monomer containing one polymerizable ethylene linkage and an aliphatic hydrocarbon chain of from 8 to 18 carbon atoms With a monomer containing a nitrogen atom and one polymerizable ethylene linkage; and

from about 0.0001 to about 0.01 Wt. percent of a dialkyl dimethyl ammonium nitrite wherein the alkyl groups are principally C -C radicals; said composition having enhanced water tolerance and anti-rust properties.

2. A petroleum distillate fuel composition having enhanced anti-rust and water-resistant properties which comprises a petroleum distillate fuel having a boiling range between about 250 and about 750 F. to which have "been added:

from about 0.001 to about 0.05 wt. percent of an ashless oil-soluble polymeric dispersant stabilizing additive selected from the group consisting of (a) a copolymer of an alkyl chloropropylene-oxy mixed ester of an unsaturated conjugated dibasic acid and a polymcrizable organic monomer containing a vinyl group and (b) a nitrogen-containing addition-type copolymer of an amine-free monomer containing one polymerizable ethylene linkage and an aliphatic hydrocarbon chain of from 8 to 18 carbon atoms with a monomer containing a nitrogen atom and one polymerizable ethylene linkage; and

from about 00002 to about 0.002 wt. percent of a dialkyl dimethyl ammonium nitrite in which at least 55% of the alkyl groups are C to C radicals.

3. A composition as defined by claim 1 wherein said dialkyl dimethyl ammonium nitrite comprises dicoco dimethyl ammonium nitrite.

4. A composition as defined by claim 1 wherein there is also present in the composition from about 0.0005 to about 0.8 wt, percent of a tertiary alkyl primary amine having a tertiary carbon atom to which are attached an alkyl group of from 1 to 3 carbon atoms and an alkyl group of from 5 to 21 carbons atoms.

5. A composition as defined by claim 4 wherein said tertiary alkyl primary amine is one having an alkyl group of from 12 to 14 carbon atoms.

6. A composition as defined by claim 1 wherein said dispersant is a copolymer of beta dimethyl aminoethyl methacrylate and the methacrylate ester of mixed coconut oil alcohols predominating in lauryl alcohol.

References Cited UNITED STATES PATENTS 2,321,517 6/1943 Rosen 51-5 2,563,764 8/ 1951 Wachter et al. 123-1 2,643,178 6/1953 Wachter et a1 21-2.5 X 3,008,813 11/1961 Siegel 44-62 FOREIGN PATENTS 798,620 7/ 8 Great Britain.

DANIEL E. WYMAN, Primary Examiner. W. I. SHINE, Assistant Examiner. 

1. A LIQUID PETROLEUM DISTILLATE OIL BOILING IN THE RANGE BETWEEN ABOUT 75*F. AND ABOUT 900*F TO WHICH HAVE BEEN ADDED: FROM ABOUT 0.0005 TO 1 WT. PERCENT OF AN ASHLESS OILSOLUBLE POLYMERIC DISPERSANT STABILIZING ADDITIVE SELECTED FROM THE GROUP CONSISTING OF (A) A COPOLYMER OF AN ALKYL CHLOROPROPYLENE-OXY MIXED ESTER OF AN UNSATURATED CONJUGATED DIBASIC ACID AND A POLYMERIZABLE ORGANIC MONOMER CONTAINING A VINYL GROUP AND (B) A NITROGEN-CONTAINING ADDITION-TYPE COPOLYMER OF AN AMINE-FREE MONOMER CONTAINING ONE POLYMERIZABLE ETHYLENE LINKAGE AND AN ALIPHATIC HYDROCARBON CHAIN OF FROM 8 TO 18 CARBON ATOMS WITH A MONOMER CONTAINING A NITROGEN ATOM AND ONE POLYMERIZABLE ETHYLENE LINKAGE; AND FROM ABOUT 0.0001 TO ABOUT 0.01 WT. PERCENT OF A DIALKYL DIMETHYL AMMONIUM NITRITE WHEREIN THE ALKYL GROUPS ARE PRINCIPALLY C12-C14 RADICALS; SAID COMPOSITION HAVING ENHANCED WATER TOLERANCE AND ANTI-RUST PROPERTIES. 